Releasable starter jaw holding means



April 5, 1950 c. s. METSGER RELEASABLE STARTER JAW HOLDING MEANS Filed Nov. 1.2, 1946 INVENTOR L'HHHL E5 5. ME 7555/? ATTORNEY atented Apr 25, 1950 RELEASAIBLE STARTER JAW HOLDING MEANS Charles S. Metsger, Lodi, N. it, assignor to Ben-- dix Aviation Corporation, Teterboro, N; J., a corporation of Delaware Application November 12, 1946, Serial N '0. 709,272

6 Claims. (Cl. 19242) The invention hereof relates to means for holding a starter jaw or the like against rotation whereby it is moved axially into engagement with an engine element, and for releasing the jaw from such holding for rotation to start, the engine.

In a, direct cranking starter of a usual type, the starter jaw is frictionaily held against rota tion while it i being moved axiall to engage an eng'ne jaw element or the like, whereupon it is rotated to start the engine While still being frictionally held as aforesaid.

Such prior structure imposes the friction load or drag on the starter jaw during rotation of the latter, which causes loss of operating efliciency and is otherwise disadvantageous.

Among the objects of the present invention are to overcome the above-mentioned disadvantages and to do so by novel eiiective means.

Another object is to automatically release the holding effect of the holdin means on a starter jaw at, or about, the time it engages the engine jaw and rotates to start the engine, which means automatically resumes its holding e-liect upon retraction of the jaw.

Another object is to provide a device of the above-indicated character which is simple and" durable in construction, economical to manufacture, and effective inits operation.

These and other objects and features of the invention are pointed out in the following description in terms of the embodiment thereof which is shown the accompanying drawing. It is to be understood, however, that the drawing is for the purpose of illustration only, and is not designed as a definition of the limits of the invention, reference being-had t the'appended' claims for this purpose.

In the drawing:

Figure l is a, side view, partially in section and partially in elevation, of a portion of a direct cranking starter structure, embodying the invention in one form and Figure 2 is a View, similar to a portion of Figure 1, showing the invention in modified form.

In Figure l, which shows only so much of the starter sufficient for an understanding of the invention, the device comprises a rotor or member ill having jaws l2 and adapted for axial movement, from its retracted position shown, to a position of engagement with an enginejaw orrotor load element l4 having jaws It.

A hollow shank portion I? of the member l0 cooperates with means l8 in-accordance withthe invention, 1302100 later more fully described; and has an innerspline connection. 20 toa hollow screw shaft 22 having long-lead screw thread connec tion to a hollow axially stationary rotative nut 24.

Shoulders 2t and 28, on the shaft 22 and the nut 2%, respectively, engage each other, after rotation of the nut has caused movement of the shaft to the left, as viewed in the drawing; and the member iii has been correspondingly moved by the shat, through the intermediary of a spring til, into engagement with the engine element it, to rotate the elements Hi and Ii to start the engine.

A member 32; held by a nut at in an opening in a central web portion of the member lit; has; a sealin ring it, compressed by the nut between the members Ill and (52, and is provided with a flange fitbehind a flange it oftne'screw shaft 22. The spring 39 extends between the flange 3'3 and a backing ring 42 held to the shaft 22-; as by a: lock ring it.

A barrel 45, rotatively journaled in ahousing portion 43, has a closed end wall 56, from which project trunnio'ns 52 carrying planet gears 5ihelcl in place, as by a ring 56, and engaging an orbital gear 58 fixed to theheusing portion ill, and a sun gear 63 fixed to a shaft 62 ournaled, as hy needle bearings 55, in a tubular portion 660i anannular plate-like member $8 between the shaft 22 and the nut 24 at one side, and thewall 50, at the other side. The tubular portion is closed at its left hand end, as by a disc ill.

A. torque limiting disc pack it, having discs splined tothe nut E i and. the barrel 4-6; res-pew tiveiy, is pressed against the member 68 bys-pringsi l, the degree of pressure of which is regulated by a: ring nut 'lfiiin-the barrel 4'5;

The shaft 62 is connected to other elementscornpleting a gear train for reducingthe' speed of a driving or motor shaft, to the right of the structure shown, to the desired speed of the barrel 46-.

A feature of the invention resides in providing the shank i'l withra .portiontt! of given diameter, leading in the direction-of movement of the member Ill, engaging the latter tov the engine ele ment Hi, and a following shank portion 82. of; lesser diameter gradually merged into the leading shank portion Bil by an annular axially extending ramp 84.

A fluid seal 86; fixed to a housing portion as, is maintainedaround the follower shanl portion 52. in radially inwardly pressingsealing engage-- ment therewith during the axial and rotative movements of "the member" I 0.

A split ring 9%, as of'phosphor bronze, forward-- 1y of the seal 86, is maintainedin position by rings 9% and SLfixed to the-housing tfi in radiah 1y inwardly pressing frictional engagement with the leading shank portion 86 until the jaw member ill engages the jaws [6 of the engine element l4, whereupon the engine element it holds the starter jaw member if) for the completion of its axial movement, during which the friction ring 90 slides axially downwardly of the ramp 8G to position radially opposite the follower shank portion 82, in non-friction relation thereto during the rotative movement of the member it]. The ramp 8% provides for the return of the friction ring $6 to position on the leading shank portion 80 when the starter jaw member if) is reversely axially moved to its retracted position, shown.

In Figure 2, in which corresponding parts are designated by corresponding reference numerals, the modification therein shown is similar in construction and operation to the device of Figure 1, with the exceptions that the leading shank portion 86 is longer, the seal 86 operates on the leading portion, instead of on the follower portion 82, and other changes of design are effected in accordance with these differences, each form having advantages over the other.

Although only two embodiments of the invention have been illustrated and described, various changes in the form and relative arrangements of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention. Reference is, therefore, to be had to the appended claims for a definition of the limits of the invention.

What is claimed is:

1. In a direct cranking engine starter comprising a housing, an axially stationary rotatably driven hollow nut, a screw shaft in said nut adapted for axial movement in response to initial rotatably driven movement of said nut and for subsequent rotative movement by the nut, and spring means, the combination of a starter jaw member adapted for movement from retracted position to a position axially outwardly of said housing by said shaft through the intermediary of said spring means during said initial movement for engaging an engine jaw element and for rotative movement by said shaft for rotating the engine jaw element upon said subsequent rotative movement, said jaw member having a shank portion of given diameter leading in the direction of axial movement of said member engaging the latter to the engine element and a following shank portion of lesser diameter gradually merged into said leading shank portion by an annular axially extending ramp, a fluid seal fixed to said housing and maintained around one of said shank portions in radially inwardly pressing sealing engagement therewith during said axial and rotative movements, and a split rin maintained in position by said housing in radially inwardly pressing frictional engagement with said leading shank portion until said jaw member engages the jaws of the engine element, whereupon the engine element holds said starter jaw member for the completion of said axial movement during which said friction ring slides axially downwardly of said ramp to position radially opposite said following shank portion in non-friction relation thereto during said rotative movement, said ramp providing for the return of the friction ring to said leading shank portion when the starter jaw member is reversely axially moved to said retracted position.

2. In a direct cranking engine starter and the like comprising an axially stationary rotatably driven nut, and a screw shaft adapted for axial movement in response to initial rotative movement of said nut and for subsequent rotative movement by the nut, the combination of means including a starter member adapting the latter for axial movement by said shaft during said initial movement to position engaging an engine element and for rotative movement by said shaft for rotating the engine element upon said subsequent movement, said member having a shank portion of given diameter leading in the direction of said position and a follower shank portion of lesser diameter joined to said leading shank portion by an annular axially extending substantially ramp portion, and a substantially ring-like member maintained in radially inwardly pressing frictional engagement with said leading shank portion until said member engages the engine element for resistance by the latter against rotation, whereupon the engine element holds said member for the completion of said axial movement thereof during which said friction ring rides axially downwardly of said ramp to position radially opposite said following shank portion in non-frictional relation thereto during said rotative movement, said ramp providing for the return of the friction ring to said leading shank portion when said member is reversely axially moved to said intracted position.

3. In a direct cranking engine starter and the like comprising an axially stationary rotatably driven nut, and a screw shaft adapted for axial movement in response to initial rotative movement of said nut and for subsequent rotative movement by th nut, the combination of means including a starter member adapting the latter for axial movement by said shaft during said initial movement to position engaging an engine element and for rotative movement by said shaft for rotating th engine element upon said subsequent movement, said member having a shank portion of given diameter leading in the direction of said position and a follower shank portion of smaller diameter joined to said leading shank port on by an annular axially extending substantially ramp portion, and a substantially ring like member in radially inwardly pressing frictional engagement with said leading shank portion until said member engages the engine element for resistance by the latter against rotation, whereupon the eng ne element holds said member for the completion of said axial movement thereof during which said friction ring rides axially downwardly of said ramp to position radially opposite said following shank portion in non-frictional relation thereto during said rotative movement.

4. In a direct cranking engine starter and the like comprising an axially stationary rotatably driven nut, and a screw shaft adapted for axial movement in response to initial rotative movement of said nut and for subsequent rotative movement by the nut, the combination of means including a starter member adapting the latter for axial movement by said shaft during said initial movement to position engaging an engine element and for rotative movement by said shaft for rotating the engine element upon said subsequent movement, said starter member having a shank portion of given diameter leading in the direction of said position and follower shank portion of less diameter joined to the leading shank portion by an annular ramp, fluid seal means cooperating with one of said shank portions, and holding means cooperating with said leading shank portion preventing rotation and providing for said axial movement of said memher until the latter engages the engine element fo res stance by the latter against rotation and said holding means slides downwardly on said ramp whereupon the engine element holds said member for the completion of said axial movement thereof and the rotation preventing effect of said holding means is released.

5. In a direct cranking engine starter and the like, an axially movable starter clutch member adapted to be held against rotative movement for effecting its axial movement in one direction from initial position for engagement with an engine clutch element for rotating the latter to start th engine, the starter clutch member having a shank portionof given diameter leading in said direction and a follower shank portion of less diameter joined to the leadingshankportion by annular means, means cooperating with one of said shank portions fo sealing the clutch member during its axial and rotative movements, and means c0- operating with the lead ng shank portion in given position holding the clutch member against rotathe latter during which the annular means cooperates with the holding means in movement of the latter from said position on the leading shank portion to a location on said follower shank portion released from holding relation to the clutch member, the holding means being maintained in released location during the clutch member rotative movement and said annular means cooperating with the holding means during the return of the clutch member to the initial position of the latter to efiect movement of the holding means from said released location on the follower shank portion to the said holding position of the latter on the leading shank portion to resume its holding of the starter clutch member.

6. In a direct cranking engine starter and the like, a rotative clutch member axially movable into engagement with a rotative engine element and adapted to rotate the latter to start the engine, means cooperating with one portion of the clutch member for sealing the clutch member during its axial and rotative movements, driving means, transmission means between the driving means and the clutch member including means adapted to eflfect the axial and rotative clutch member movements, a shaft for said clutch member, said shaft including first and second portions, means cooperating with the first portion of the shaft of the clutch member to hold the clutch member against rotation by the driving means to effect said engagement, and said second portion of the clutch shaft being adapted to release the holding means upon movement of the clutch member into said engagement and thereby permit the driving means to rotate the clutch member, the holding means being arranged to resume holding position on the first portion of the shaft upon return of the clutch member to initial position.

CHARLES S. METSGER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,730,220 Lansing Oct. 1, 1929 2,226,227 Hodges Dec. 24, 1940 2,329,929 Nardone Sept. 21, 1943 

